As the third round of talks on Iran's nuclear program begins in Geneva, the US must realize it was the election of Hassan Rouhani, not sanctions alone, that brought Iran to the negotiating table. Continuing sanctions will undermine the new government's efforts for a peace deal.

Iran's Supreme Leader Ayatollah Ali Khamenei delivers a speech to members of the paramilitary Basij force in Tehran, Iran. Khamenei says pressure from economic sanctions will never force the country into unwelcome concessions and blasted US government policies, but said Iran seeks 'friendly' relations with the US.

Cambridge, Mass. — As the third round of talks begins today in Geneva on the Iranian nuclear program, it is imperative that the United States not overplay its hand at the negotiation table. One of the dangers the US must take heed of is falling for the argument that Iran has entered negotiations out of weakness due to the heavy costs of sanctions imposed on the country and its increasing economic and political vulnerability. Conclusions based on this reading of events would suggest that the US can take its time in negotiating with Iran without providing any sanctions relief or that sanctions can be effectively continued or increased with positive results.

The problem with this narrative is that it is largely divorced from the actual processes that have produced a change in Iranian behavior. It ignores the domestic and internal politics of the Islamic Republic of Iran by treating the regime as a unitary actor and downplays the critical importance of the election of President Hassan Rouhani to office and the delicate political balancing act he is involved in on the domestic political scene.

Yes, sanctions played a part in changing Iran’s behavior, but not because they forced Iran to return to the negotiation table out of fear of economic collapse. Rather, sanctions contributed to a transformation of the balance of power within the Iranian political system that had been already underway since 2009 – prior to the enactment of the current sanctions regime. Sanctions helped pave the way for a Rouhani victory in the 2013 presidential elections by perpetuating the divide within the conservative forces of the Iranian establishment over the economy. The sanctions also cemented an emerging alliance among members of the ruling elite against the administration of Mahmoud Ahmadinejad.

The election – and not sanctions – was therefore the key to Iran’s shift on foreign policy and nuclear negotiations that we so strikingly see today. The victory of another candidate, such as former nuclear negotiator Saeed Jalili, would not have produced such a change in foreign policy despite the presence of the same sanctions regime. The impact of sanctions should accordingly be viewed through the lens of electoral turnover and the domestic shifts of power that brought Mr. Rouhani to office.

The current re-alignment of forces in Iran and the country’s intention to reach out to the international community consequently present the US with both a momentous opportunity to be seized and an important condition to be safeguarded. The success of the Rouhani administration and his coalition alliance is critical for reaching a mutually beneficial deal on the nuclear program and for advancing a more moderate and politically inclusive Iran.

The persistence of sanctions, however, without any meaningful relief or significant incentives, will only undermine the Rouhani administration and inhibit the potential for such a resolution from taking shape. Not only will continued sanctions contribute to the wall of mistrust between the US and Iran, but they will strengthen the hand of Iranian hardliners.

A recalibration of political forces back toward the hardline elite would divide the cross-factional coalition supporting the Rouhani presidency. If members of the Iranian elite perceive that the door to a renewed engagement with the world financial markets will be closed to them for the medium- to long-term then many of them will alter their calculations and gravitate toward an alternative political and economic program – one of domestic self-sufficiency and resistance that has been increasingly called for by hardliners.

In negotiating over the nuclear program with Iran, it is critical that the US and its partners get the sanctions narrative right. While sanctions contributed to an ongoing re-alignment of political factions that was conducive to Rouhani’s electoral victory and the shift in Iranian foreign policy, they alone didn’t bring Iran to the negotiating table. And their continuance can also undermine the new government that is now in power.

Given the rare and opportune environment to reach a negotiated deal with Iran, the US would be best served to devise a meaningful incentives package with an eye on the domestic Iranian political scene rather than increasing sanctions on Iran.

Payam Mohseni is a visiting assistant professor in the Department of Government at Harvard University and a postdoctoral research fellow in the International Security Program at the Harvard Kennedy School’s Belfer Center for Science and International Affairs.